function get(url,params,callback,header){

    let temp = []
    for(key in params){
        temp.push(`${key}=${params[key]}`)
    }
   console.log(temp.join("&"));
const xhr = new XMLHttpRequest()
xhr.open('get',`${url}?${temp.join("&")}`)
xhr.onreadystatechange = function(){
    if(xhr.readyState ===4){
        if(xhr.status===200){
            let res = JSON.parse(xhr.responseText)
            callback(res)
        }
    }
}
for(key in header){
    xhr.setRequestHeader(`${key}`,`${header[key]}`)
}
xhr.send()
}